Coil-former.



D. MILLER.

COIL FORMER.

APPLICATION FILED MAY 31, 1910.

Patented July 1 19112.

I n vex-Ito? Witnesses:

'David Miller B9 His aqttorfjes.

"UNITED STATES PATENT OFFICE.

navm MILLER, or scnENEcrAJJY," new roux, nssrenon 'ro GENERAL nrnc'rprc comrm, A conronnrron or NEW YORK. r

corn-Fortune.

To all whom it may concern.-

"Be it known that I, DAVI MILLER, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Coil-Formers, of which the following is a specification.

The present invention relates to the art of metal working and more especially to the manufacture of edgewound coils from flat strips or ribbons of metal.

It is old in the art to make a coilby bending a strip about an axis at right angles to its plane'so that the strip becomes disposed in a plain helix with substantially radial elements. These plain edgewound .coils are used without practical difiiculties in solenoids or other places where the individual convolutions may be supported and held in posit-ion transversely, but in those uses of p the coil where the individual convolutions v as a consequence, it has been proposed to are required to be spaced apart without supporting means, as when used as radiator coils, much trouble has been experienced in securing them in the desired relation, and,

provide the convolutions of the coil with integral flanges at their inner edges, which flanges are adapted to be attached to the pipe or other support from which radiation is to -be effected. Coils of the latter form,

altho ugh recognized as highly desirable,

have not, previous to my invention, gone 'eral use for the reason that it has been impracticable to manufacture them economically. u

The object of my invention is to provide meansfor manufacturing economically I edgewound coils having integral flanges.

In carrying out my invention, a forming'die which is adapted relatively wideand thin metal strips or rib- I. employ bons and simultaneously form therein a limgltudinal fold and a radial helix as the strip passes to the mandrel about which it 1s a wound.

. Fora more complete understanding of my invention, refere 'ce maybe had to the accompanying drawing forming a part of this spec1fication, in which- Figure 1 is a plan of the mandrel and a section of the coil forming die with a flanged coil shown in process-of formation; Fig. 2 isa perspective view of'the left-hand 560 Specification of ietters Patent.

' tion of the die;

to receive Fig. 3 is a similar View of the right-hand are sections taken onlines 4-4,. 5-5 and 6-6 of Fig. 1; Fig. 7 is a perspective view; and Fig. 8 a bottom plan of the folding wedge.

driving the mandrel 1, but it is to be understood that any machine tool, such as a lathe, may be employed for that purpose. The die shown in the drawing may .be carried by the tool carriage of the lathe and requires no special feed or guide," since the thread of the coilformed operates to force the die longit'udinally of the mandrel automatically. The left-hand section of the die has in its forward end a steel helix 2 with its turns spaced to permit'the formed coil to pass between them and operating to support'the strip of metal 3 sidewise, and the righthand section of the die has a similar steel helix 4; extending somewhat over 180 degrees,,and leading from or tangential to the lower portion is a channel having a folding substantially fiat and gradually merged into :of the helix 4.. 'In order to prevent buckling of the strip as it is passed over the deedge of the surface, an

' ing surface 5, a folding wedge 8, as shown in Figs. -7 and 8, .is provided wlth a surface complementary to the foldin surface 5, so that when the parts are assem be a passage-way, between the folding wedge uniform transverse dimensions.- The front end of the wed e is provided with a projection 9 adapt ,to' extend up against the tongue 7 and to operate to hold, the turned mandrel. The right-hand section of the die is also provided with a bushing 10 serving as a centering bearing for the mandrel and having a crown flan e 11 extending a short distance into-the ie with itsinner 'Patented-July16'J 912.

section; Figs. 4, 5, and 6.

The drawings do not show any device for surface 5, which at the rear end of the die is Y pressed folding surface 5, a guide groove 6 adjacent the inj led there will u 8 and the folding surface 5 of substantially over-portion on the strip until it reaches the a right angle as it joins the lower portion ment edge formed helically to serve as an abutshown in Fig. 6.

- The matter of starting the operation of forming an edgewound coil in any case presents many practical difliculties, and the difliculties in starting a flanged edgewound coil is much greater than in the case of a plain coil, for the reason that the friction between the strip and die is much greater and the tendency to rupture the strip is so reat that a slight percentage of increase in riction at the entrance to the die will operate to break the strip as it is drawn in. It is for this purpose that the folding wedge 8 is made comparatively loose, and also in order that-the strip may be passed through the die and connected to the mandrel, as shown at the left of-Fig. 1,- before any tension is put upon it, it is necessary that the Wedge be detachable. After the strip has been attached to the mandrel, the key is forced home and the right and left sections of the die clamped together by screws 12 or other means.

I do not desire to restrict myself to the particular construction or arrangement of parts here shown and described, since it is apparent that they may be changed and modified without departing from my invention. I

- What I claim as new and desire to secure by Letters Patent of the United States, is,

I. A die for making flanged edgewound coils having fixed surfaces to fold the coil for the edge of the coil flange, as-

strip longitudinally, and means for guiding and supporting on 'all sides the bent strip during the coiling.

2. A fixed die for making-flanged edgewound coils having a' guide helix, and a folding passage-way leading thereto.

3. The combination of a mandrel, and a die adjacent thereto having fixed surfaces for longitudinally folding a strip of metal and simultaneously forming a radial helix in one portion thereof and a flat helix in the other portion.

4. A sectional edgewound coils, each section having a fixed folding surface and a forming helix.

5. A die for making flanged edgewound coils comprising two sections, one of which has a guide helix and the other of-which has a guide helix and a depressed folding surface, a wedge having a complementary folding surface, and means for holding the two sections and wedge in fixed relation.

6. A die 'for making flanged edgewound die for making flanged coils having a channel formed with a fold- DAVID MILLEIi.

Witnesses; v BENJAMIN B. HULL, CARL A. SALMONSEN." 

